2002
DOI: 10.1021/np0202475
|View full text |Cite
|
Sign up to set email alerts
|

New Chemical Constituents ofEuphorbiaquinquecostataand Absolute Configuration Assignment by a Convenient Mosher Ester Procedure Carried Out in NMR Tubes

Abstract: Two new compounds, an ent-isopimarane-type diterpene, 3alpha,12alpha-dihydroxy-ent-8(14),15-isopimaradien-18-al (1), and a dihydrobenzo[b]furan neolignan, (-)-trans-9-acetyl-4,9'-di-O-methyl-3'-de-O-methyldehydrodiconiferyl alcohol (2), along with five known compounds, 7,7'-dihydroxy-6,8'-bicoumarin (bicoumol) (3), 3,4-dimethoxycinnamaldehyde (4), 6-hydroxy-7-methoxycoumarin (isoscopoletin), N-butylaniline, and vanillin, have been isolated from an ethyl acetate-soluble extract of the stem wood of Euphorbiaquin… Show more

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...
1
1
1
1

Citation Types

6
209
0

Year Published

2005
2005
2018
2018

Publication Types

Select...
5
5

Relationship

0
10

Authors

Journals

citations
Cited by 213 publications
(215 citation statements)
references
References 27 publications
6
209
0
Order By: Relevance
“…The remaining residue was dissolved in pyridine (200 µL), to which 2 mg of L-cysteine methyl ester hydrochloride was added. The mixture was stirred at 60 °C for 1 h; then 50 µL of o-tolyl isothiocyanate was added, and the mixture was stirred at 60 °C for another 1 h. The reaction mixture was directly analyzed by standard C 18 [17] To a stirred solution of 3a (10 mg) in MeOH (2 mL), NaOH (1 mg) was added. The mixture was stirred at room temperature for 0.5 h to obtain 3b, and then 3b (7.2 mg) was transferred into a clean NMR tube and was dried completely under the vacuum of an oil pump.…”
Section: Computational Methods For Electronic Circular Dichroismmentioning
confidence: 99%
“…The remaining residue was dissolved in pyridine (200 µL), to which 2 mg of L-cysteine methyl ester hydrochloride was added. The mixture was stirred at 60 °C for 1 h; then 50 µL of o-tolyl isothiocyanate was added, and the mixture was stirred at 60 °C for another 1 h. The reaction mixture was directly analyzed by standard C 18 [17] To a stirred solution of 3a (10 mg) in MeOH (2 mL), NaOH (1 mg) was added. The mixture was stirred at room temperature for 0.5 h to obtain 3b, and then 3b (7.2 mg) was transferred into a clean NMR tube and was dried completely under the vacuum of an oil pump.…”
Section: Computational Methods For Electronic Circular Dichroismmentioning
confidence: 99%
“…58,59 In brief, two portions of each compound (1 mg) were added into two NMR tubes, and dried completely. Pyridine-d 5 was added to both tubes (each 0.5 mL).…”
Section: Preparation Of the (R) And (S)-mtpa Ester Derivatives Of Commentioning
confidence: 99%
“…The configuration of the isolates, including the absolute configuration of the secondary hydroxy groups was determined using a modified Mosher ester methodology [75,78]. Using this technique, the C-12 hydroxy group in the side chain of the clerodane-type diterpenes isolated was determined as having an S absolute configuration [36].…”
Section: Biological Evaluation Of Callicarpa Extracts and Pure Compoumentioning
confidence: 99%